Furnace wall and block unit for making the same



Nov. 24, 1936. EH, BANKE T msmzz FURNACE WALL AND BLOCK UNIT FOR MAKINGTHE SAME Filed April 12, 1935 2 Sheets-Sheet l ZZZ/67 (for! Nov. 24,1936. F. H. BANKERT FURNACE WALL AND BLOCK UNIT FOR MAKING THE SAME 2Sheets-Sheet 2 Filed Ap E. L; 2 a J 2 Z 2 H 2/?! e flpd E1307! PatentedNov. 24, 1936 PATENT OFFICE FURNACE WALL AND BLOCK UNIT FOR- MAKING THESAME Fred H. Bankert, Ottawa, 111., assignor to Chicago Retort & FireBrick 60., Chicago, 111., a

corporation of Illinois Application April 12, 1935, Serial No. 15,956 I6 Claims. (01. 72-101) My invention relates to furnace walls and blocksfor making the same and is more particularly concerned with theso-called air-cooled type of wall and the component block units.

In the operation of modern furnaces, the tendency is towardsincreasingly higher temperatures and this development has become morepronounced with the advent of pulverized coal. Solid furnace wallscannot withstand these higher temperatures and this condition obtainsparticularly in those regions where the coal burned has an' ash fusingtemperature that is either medium or low; The chemical aflinity, in thepresence of'the high temperature, between the basic ash and the acidrefractory in the wall necessarily requires that the solid wall type ofinstallation either operate at low temperatures, or, in other words, lowcapacity, or be subject to high maintenance cost because of thenecessity for frequently renewing the furnace wall.

It has been ascertained that if the furnace wall is cooled in somemanner so that it has a temperature below the slagging point of the ash,it is possible to prevent the formation of the corrosive, molten slag. Acommon furnace wall construction of this kind is composed of a block orunit having a portion which is exposed to the fire and an externalportion which is suitably anchored to the outside framework of thefurnace, these portions being connected by a curved and tapering neck.When these blocks are laid in courses to build a furnace wall, there isthus provided a furnace section and an exterior sec- 4 tion which arespaced from each other sufficiently to provide a passage therebetweenfor the circulation of cooling air.

While the foregoing type of construction has proved effective as regardsthe cooling of the furnace section of the wall, experience has indicatedthat this arrangement is subject to certain objectionable, operatingdisadvantages. The furnace section of these blocks are exposed to veryhigh temperatures, while the anchored section of the same block iscomparatively cool so that differential strains are set up in the blocksto an extent. that frequently cause the neck connecting the sections tocrack, thus entailing a replacement of the entire block. Thisreplacement also becomes necessary where the action, of gases and slagsin the furnace has destroyed the furnace section of the block, althoughthe exterior section is still in a usable condition. Such blocks aretherefore characterized by a high maintenance cost. Moreover, as atpresent designed, these blocks are of such a size and shape that. theymust be manufactured by an expensive hand type of molding process, sincethey cannot be made by the ordinary machinery employed for manufacturingother refractory shapes. I 5

. It is, therefore, one object of my invention to devise a unit which isadapted to form a part of an air-cooled furnace wall and which is composed of separable furnace and exterior blocks so arranged that thefurnace blocks can be replaced without disturbing or requiring areplacement of the exterior blocks.

A further object is to devise a unit of the character indicated which isso disposed with reference to other units that when laid in courses toform a furnace wall, suflicient space is provided between the blocks toprovide for a free circulation of cooling air, a high rate of heattransfer through the furnace block portion of the unit and a high ratioof heat-absorbing surface to heat-dissipating surface, the furnaceblocks being additionally so connected to the exterior or anchoredblocks of the wall that the former are capacitated to move independentlyof the exterior wall section, whereby any tend- 25 ency to set updifferential strains in the unit is substantially eliminated.

A further object is to provide a unit in which the furnace and exterioror anchored blocks are linked together by a substantially universalconnection and, especially, one operating on the ball and socketprinciple, so that the block can expand or contract in any directionwithout substantial strain. Y

A further object is to devise a unit which is composed of separableparts, whereby the furnace block portions thereof can be made of aspecial and more expensive refractory material, while the other parts ofthe unit can be made of ordinary refractory clay.

A further object is to provide a unit so constructed and arranged as tosize and shape that they can be readily formed by machines now in commonuse in the industry.

vA further. object is to devise a fire wall constructed of the foregoingunits which will be characterized by a considerably greater .free airspace per square foot of heating surface than air-cooled furnace wallsnow in common use, I thus providing for the circulation of a greater 50volume of air per unit of wall area and raising the rate of transferacross the furnace blocks to thereby increase the emciency of the walland the life of they refractory.

- These and further objects of my invention will 55 be set forth in thefollowing specification, reference being had to the accompanyingdrawings, and the novel means by which said objects are effectuated willbe definitely pointed out in the claims.

In the drawings:

Figure 1 is a perspective view, partly in section, of a portion of afurnace wall built with my improved unit.

Fig. 2 is an enlarged, perspective view of a complete wall unit.

Fig. 3 is a perspective view of one of the parts of the furnace blockportion of the unit.

Fig. 4 is a sectional elevation of the unit showing the link employed toconnect the furnace and exterior or anchored blocks of the unit. 1 Fig.5 is a plan view of the lowermost part of the unit as viewed along theline 5-5 in Fi 4, looking in the direction of the arrows.

ig. 6 is a perspective view of the connecting link between the blocks.

Fig. '7 is a section along the line 1-1 in Fig. 4, looking in thedirection of the arrows and showing an end view of the anchor which isemployed to fasten the exterior blocks of the unit to the,

framework of the furnace.

Referring to the drawings, the numeral l0 designates the outer sheathingor covering of the furnace which is inner-lined by the customary layerof insulation I A portion of the usual framework of the furnace isindicated by the spaced, parallel Z-bars |2 to which are secured theouter ends of anchors I3 whose inner ends are enlarged toprovidedisk-heads I4 that are unit l5 when laid in courses to compose afurnace wall provides a furnace section It and an exterior sectionwhich-are separated by a space l8 through which is circulated thecooling air.

In general, my improved wall unit I5 is composed of three generic parts,namely, an inner or furnace block IS, an exterior or anchored block 20and a link which connects these blocks together, as hereinafterdescribed. The furnace block I9 is preferably composed of two parts 2|and 22, while the exterior block 20 is likewise composed of two parts 23and 24, each of these parts being generally of a rectangularconformation, and when employed to form walls, the parts 22. and 24 arelaid upon the parts 2| and 23, respectively, in the usual courses.

The furnace block part 2| is provided on its rear face with an inwardlyextending boss 25 which is provided with a cavity 23, preferably shapedas a part-sphere, and which communicates with the innermost face of theboss 23 by means of a groove 21. The block part 22 is formed similarlyto the block part 2|, so that when the part 22 is laid on the part 2|,the partispherical cavities 23 in the bosses 25 complement each other,as do the bosses 23 to pro- 1 wide a complete and preferably circularboss.

Also, the edge faces of the blocks 2| and 22 are preferably providedwith the groove 28 and tongue 29 which interlock when the parts are laidin the usual manner to minimize leakage of air and/or gas through theJoints between the block arts.

The exterior block part 23 is also provided on its inner face with aparti-circularly shaped boss 30 which projects, when the units areassembled in a complete wall, toward the similarly shaped boss 25 on theblock 2|. As before, the boss 30 is alsoprovided with a parti-sphericalshaped cavity 3| which connects with the inner face of the boss 30 bymeans of a groove 32. The block part 23 is also provided with a recess33 that is spaced from the cavity 3| and which is intended to receivesubstantially one-half of the head I4 of the anchor l3, as well as theconnecting neck portion of this anchor, whereby the' block part 23. isanchored to the framework of the furnace. The block part 24 is shapedand arranged in a manner identical to that above described for the blockpart 23, so that when the former block is laid upon the latter block, asclearly shown in Fig. 2, there is formed a circularly shaped boss by thecomplementary portions 30 that extends toward the similarly shaped bossformed by the bosses 25, the former boss also having a sphericallyshaped cavity similar to that present in the boss formed by the bosspart 25.

In building a wall with my improved unit, the lowermost courses thereofare laid by the block parts 2| and 23. The spacing of these block partsprovides the cooling air passage I8 as determined by a connector link 35which is preferably shaped and arranged as a dumbbell and whoseball-shaped ends 36 and 31 are placed in the cavities 26 and 3|, withthe connecting portion of the link between the ends thereof lying in thegrooves 21 and 32. The up per block parts 22 and 24 are then laid on theparts 2| and 23, as indicated in Figs. 2 and 4, thus completing thelowermost course of units.

Preferably, the diameter of each connector is somewhat less than thediameter of the cavity which receives them, and the same relation existsbetween the diameter of the cylindrical connecting portion of the linkand the grooves 2T and 32. is fixed to the framework of the furnace, itis therefore possible for the furnace block I! to move substantially inany direction while expending or contracting without any strain beingset up in the unit. Moreover, it will be noted from Fig. 4, that a space38 is provided between the ends of the bosses provided on the innerfaces of the furnace and exterior block, so that the link 35 is alsoexposed to the cooling action of the circulating air.

With my improved unit, it is possible to make the furnace blocks I9 ofspecial and more expensive refractory material, compared to thecomposition of the exterior blocks 20, thereby permitting the use ofhigher temperatures in the furnace without any reduction in thelongevity of the unit. Also when it does become necessary to replace thefurnace block portions of the unit, the nature of the construction issuch that the exterior blocks 20 need not be disturbed which results ina clear saving over existing practice and a consequent saving in themaintenance cost of furnace walls.

The staggered or echeloned disposition of the bosses on the inner facesof the furnace and exterior blocks enables the, air to circulate freelyin the passage l3, while at the same time causing frequent changes orreversals in 'directions of the moving air to thereby provide for abetter wiping and heat-absorbing action with respect to the inner facesof the furnace blocks Since the exterior block 20 of the unit and theirattached bosses. Finally, each of the component parts of my improvedunit can be readily made by any of the machines now in common use in theindustry. It will also be understood that the unit is not restricted touse in the building of furnace walls, since the placing of the furnaceand exterior blocks in a horizontal position also enables them to bereadily employed in the construction of furnace floors of theair-cooled. type; hence the term wall, as used in the claims, is to beregarded as including floors and the like.

I claim:

1. A furnace wall comprising a plurality of blocks arranged in coursesto provide furnace and exterior sections spaced to provide a passage forthe circulation of cooling air between the sections, each block having aboss of substantial size projecting toward the other section andincluding a socket, and link means having parts fitting in the socketsfor connecting the furnace and exterior blocks together in pairs topermit expanding and contracting movements of the furnace sections, theends of the bosses of the furnace and exterior blocks being spaced toexpose a portion of the link means to the cooling air and the bossesacting to deflect the air currents while moving through the passage.

2. A unit comprising furnace and exterior blocks spaced to provide apassage therebetween for the circulation of cooling air and adapted tobe laid in courses to form an air-cooled furnace well, each blockcomprising a pair of complementary, separable parts each havingcomplementary socket cavities, and a link having ends receivable in thesockets to connect the furnace and exterior block parts.

3. A unit comprising furnace and exterior blocks spaced to provide apassage therebetween for the circulation of cooling air and adapted tobe laid in courses to form an air-cooled furnace wall, each blockcomprising a pair of separable parts, and link means loosely connectingthe furnace and exterior block parts.

4. A unit adapted to form part of an air-cooled furnace wall comprisingfurnace and exterior blocks spaced to provide a passage therebetween forthe circulation of cooling air, each block comprising a pair ofcomplementary separable parts each having complementary socket cavitiesand bosses of substantial size' projecting from the opposed faces ofeach toward the other parts, and a link having its ends receivable inthe sockets for connecting the furnace and exterior block partstogether, the ends of the bosses of the furnace and exterior blocksbeing spaced to expose a portion of the link to the cooling air and thebosses acting as air deflectors.

5. A block unit having the shape of a rectangular prism and adapted toform part of a furnace wall construction provided with a cooling airpassage, the unit comprising a pair of separable parts each havingcomplementary projections extending from that face which defines aportion of the passage to form a boss of substantial size for deflectingair currents moving through the passage, and each projection includingcomplementary socket cavities adapted to receive one end of a linkinterconnecting with another unit across the passage.

6. A unit adapted to form part of an air-cooled furnace wall comprisingfurnace and exterior blocks spaced to provide a passage therebetween forthe circulation of cooling air, each block comprising a pair ofcomplementary separable parts each having complementary bosses ofsubstantial size projecting from the opposed faces of each toward theother parts, the bosses including complementary socket cavities, and alink having its ends receivable in the sockets for connecting thefurnace and exterior block parts together.

FRED H. BANKERT.

